良性発作性頭位めまい症

抄録

　Benign paroxysmal positional vertigo (BPPV) is caused by either canalolithiasis or cupulolithiasis. It is usually caused by involvement of the posterior and/or horizontal semicircular canal. The movement of otoconial debris in the semicircular canal causes vertigo and positional nystagmus when patients with BPPV move their head. In regard to the location of debris in the affected semicircular canal, by sequential movement of the patient's head during the canalith repositioning procedure (CRP) the debris moves from the semicircular canal to the utricle. Although BPPV resolves spontaneously, in patients with BPPV positional vertigo in patients treated with CRP was resolved more quickly than that in untreated patients. BPPV in the bilateral canals is difficult to be resolved because CRP for one side would move debris to the cupula in the other canal. In the occasional patient who has unremitting BPPV despite conservative treatment, semicircular canal occlusion may be effective in eliminating symptoms. In patients with posterior canal type of BPPV and in patients with lateral canal type of BPPV, head movement in the sagittal plane in both cases triggers vertigo. Therefore, to decrease movement in sagittal plane in daily life for patients with intractable BPPV, we should basically educate them how to avoid movement in sagittal plane. To avoid such movement when putting on shoes, the patients should avoid wearing shoes which require laces. When looking down, the patients should squat down, not bend at the waist and lower their head. When moving, e.g., when turning to look at something, the patients should move with their whole body, not move only their head.